As automotive design evolves, there is constant effort to reduce weight and to make engine and drive train components smaller and more compact in order to conserve space. Generally, space allotments in vehicle design favor increasing space in a vehicle's cabin while reducing space in the engine compartment. As space in the engine compartment becomes smaller, it becomes more and more difficult to service a vehicle's engine. It is therefore desirable to maintain or even increase access to engine components wherever possible, even as an engine's space allotment decreases.
In order to ensure fuel efficient operation of vehicles and to minimize polluting emissions it is necessary to periodically examine and replace air filters. As an engine compartment's space decreases, it becomes more and more difficult to conveniently position and mount an air filter for inspection since in order to inspect an air filter, it is necessary to open a housing containing the air filter to observe the dirty side of the air filter. If an air filter is not positioned with its dirty side facing upwardly, then observing the condition of an air filter becomes difficult. Accordingly, there may be a tendency for mechanics to simply avoid examining air filters with the inevitable consequence that vehicles not having proper air filter maintenance not a will have lower fuel efficiency and contribute emissions to pollution. While this, of course, is difficulty if there are only a few vehicles not properly maintained, however when thousands of vehicles are not properly maintained, general fuel consumption increases and air quality is adversely affected.
Not only is it necessary to observe an air filter, but in order to completely inspect an air filter it is necessary to remove the air filter from its housing. The paucity of space can make removing an air filter difficult because the air filter is mounted against a seat within an air intake housing and may have become slightly adhered in place. Since in many rapid maintenance situations the customer waits while his or her car is serviced, the mechanic frequently removes the air filter and takes it and shows it to the customer. If the air filter resists removal, then the mechanic is more than likely to simply leave it in place and tell the customer that it is not clogged, when in fact it may well be clogged. Thus, there is a need to have air filters which are readily removable from their housings.
While engine air filters are of immediate and specific interest with respect to easy removal and replacement, the same considerations are of interest with respect to other types of air filters, or liquid filters for that matter.